• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.449-455
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• 2012

Greenhouse and laboratory experiments were conducted to determine the effects of shade treatment and substrate components on plant growth and physiological activity of Taraxacum officinale. Substrates combined with coco peat and perlite (ratio 70 : 30 and 50 : 50, v/v) showed higher growth and yield than their single substrates (p<0.05). Shade treatment also significantly reduced plant height, root length, root diameter, leaf area, chlorophyll content, and fresh weight (p<0.05), compared to no shade. Contents of total phenolics [mg chlorogenic acid equivalents (CAE) $kg^{-1}$ DW] and total flavonoids [mg naringin equivalents $kg^{-1}$ DW] showed higher amounts in shoot parts than root parts of T. officinale, with shade than no shade. The antioxidant potential of the methanol extracts from the plants dose-dependently increased. DPPH (1,1-diphenyl-2-picryl hydrazyl radical) free radical scavenging activity was higher in leaf parts than in root parts of the plants, and no shade than with shade.

• Journal of Plant Biology
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• v.17 no.1
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• pp.15-21
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• 1974

The most commonly grown economical and flue-cured tobacco cultivar Yellow Special A was used in pot-culture tests in order to study Ethrel (2-chloroethyl phosponic acid) effects on accelerating maturity of tobacco leaves in relation to the most adequate level of the chemical useful for field growing, nitrogen level in soil for the most pronounced response, and the most suitable spray period during the growth stages of pre-, post- and topping periods. The following conclusions, thus, were obtained from the present studies; 1. 500ppm Ethrel spray was reconfirmed to be adequate in the practical applications, although the extent of yellow-ripening of tobacco leaves was increased as the Ethrel level increased. The highest leevel treated resulted in causing chemically damaged lesions on leaves and early defoliation. 2. Ethrel-treated leaves showed deeper yellowish tinge to them than those without treatment, while different levels of the chemcial had less influence on the tinge. 3. An adequate level of nitrogen supply to plants favored the Ethrel response, whereas either very low or high level of nitrogen in the soil lowered the chemical effect on accelerating the yellow-ripening. When carbohydrates versus total nitrogen ratio became relatively high, the condition brought out some outstanding Ethrel effects. 4. Chlorophyll level of leaves increased as soil applications of nitrogen level increased, and that also increased carotenoid level of the tobacco leaves. Ethrel-treated leaves showed deeper orange tinge than those without treatment, while the highest level of nitrogen application showed the deepest orange tinge to tobacco leaves. 5. Pre-topping treatment (12 days before topping and flowering) resulted in almost no Ethrel response, and that treatment right on the day of topping, showed response of yellow-leaf ripening at nearly bottom-half leaves of a tobacco plant. The post-topping treatment (12 days after topping) made plants showing full response of Ethrel from bottom to the top leaves of tobacco plant in accelerating the leaf maturity. 6. The extent of Ethrel responses on accelerating yellow-ripening of tobacco leaves was discussed for the modifying influences brought about by certain environmental factors. Discussions were also made about the possible practical applications (particularly for pre-rice planting) and quality difference that may be caused by such growth environments.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.274-274
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• 2017

Temperature has an adverse effect for potential growth and development of Codonopsis lanceolata. The present study examined the responses of growth, yield and mineral element contents under temperature variables in C. lanceolata. Plant height exhibited the best result as being 2 m or higher the open field culture, while the growth is the most restricted in the $30^{\circ}C$. The open field culture also had the largest number of leaves in the early stage of growth. The number of leaves and the height tended to be increased with the temperature of $20^{\circ}C$ and $25^{\circ}C$. The number of branches showed no significance as 32 branches and 26 branches in open field culture and $20^{\circ}C$, respectively. The smallest number of branches was observed in the $30^{\circ}C$ with 15 branches. The leaf color recorded the lowest value in the open field culture unlike the growth above the ground. But all other temperature had no significance with the leaf color value between 50.0 and 52.6. The elevated temperature induced the thinner and shorter diameter and length of root. However, the root diameter was not significantly changed with the change of 1.8 cm and 2.1 cm at open field culture, with $20^{\circ}C$ and $25^{\circ}C$, respectively. The fresh weights of the primary root and lateral roots were 6.3 g and 3.1 g, respectively, at the high temperature. The result showed the thickening of the lowest part under the ground as restricted. The fresh weights of the main root and lateral root were the highest on the open field culture, 20.6 g and 12.2 g, respectively. The contents of cellulose were the highest as 4.41% in the $20^{\circ}C$, followed by the open field culture, $25^{\circ}C$ and $30^{\circ}C$. The higher temperature reduced the contents of cellulose. Moreover, P showed higher ratio in the high temperature while Ca and Mg exhibited the higher ratio towards the low temperature. On the contrary, minor quantity (less than 1%) of mineral nutrients was observed towards all temperature variables.

• Korean Journal of Soil Science and Fertilizer
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• v.50 no.5
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• pp.409-421
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• 2017

Recently Unmanned Aerial Vehicle (UAV) technology offers new opportunities for assessing crop growth condition using UAV imagery. The objective of this study was to select optimal vegetation indices and regression model for estimating of rice growth using UAV images. This study was conducted using a fixed-wing UAV (Model : Ebee) with Cannon S110 and Cannon IXUS camera during farming season in 2016 on the experiment field of National Institute of Crop Science. Before heading stage of rice, there were strong relationships between rice growth parameters (plant height, dry weight and LAI (Leaf Area Index)) and NDVI (Normalized Difference Vegetation Index) using natural exponential function ($R{\geq}0.97$). After heading stage, there were strong relationships between rice dry weight and NDVI, gNDVI (green NDVI), RVI (Ratio Vegetation Index), CI-G (Chlorophyll Index-Green) using quadratic function ($R{\leq}-0.98$). There were no apparent relationships between rice growth parameters and vegetation indices using only Red-Green-Blue band images.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.609-615
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• 2011

Forsythia saxatilis is a Korean endemic plant designated as rare and endangered by the Korea Forest Service (KFS). Growth and physiological characteristics of F. saxatilis were investigated under two different light intensities in order to figure out an appropriate growth environment for conservation and restoration of the species in its natural habitat. Shoot length, leaf size and weight, photosynthetic pigment content and photosynthetic parameters were measured for F. saxatilis grown at two experimental plots under relative light intensities (RLI) of 20% and 60% of the full sun, respectively. Fresh leaf weight of plants grown under high relative light intensities (RLI-60) exceeded that of plants grown at 20% RLI. The ratio of fresh leaf weight to leaf size at RLI-60 was 1.47 times superior comparing to that recorded at RLI-20. The content of photosynthetic pigments such as chlorophyll a, b and carotenoid were higher in plants grown at RLI-60, whereas the ratio of total chlorophyll to carotenoid content was higher in the leaves at RLI-20. Photosynthetic rate, stomatal conductance and transpiration rate at RLI-60 were, respectively, 2.5, 2.65 and 1.79 times higher comparing to those recorded at RLI-20. Water use efficiency, however, was higher at RLI-20. The chlorophyll/nitrogen ratio was 1.83 times higher at RLI-20 than at RLI-60. In contrast, the ratio of net photosynthesis to chlorophyll content at RLI-60 was 2.58 times higher than that of RLI-20. In conclusion, light intensity might be the major factor affecting growth and physiological characteristics of F. saxatilis grown under canopy of tall tree species.

• Animal Bioscience
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• v.37 no.4
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• pp.668-677
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• 2024

Objective: The current experiment was performed to investigate the influence of different dietary levels of Moringa oleifera leaf meal (MOLM) on productive performance, nutrient digestibility, blood parameters, immune response, caecal microbiota, and carcass characteristics of Muscovy ducks (Cairina moschata) during 7 to 63 d of age. Methods: A total of 240 unsexed 7-d-old ducklings were distributed into five (treatment) groups; each one contained six replicates with eight ducklings each. Birds of the first group were fed basal diet without MOLM and served as control, while the other four groups were fed basal diet with 0.25%, 0.50%, 1.0%, and 2.0% MOLM inclusion level, respectively. Results: The obtained results revealed that including MOLM in the diets significantly improved body weight, body weight gain, feed conversion ratio and economic efficiency compared with the control group. Among the different MOLM inclusion treatments, increasing MOLM inclusion level decreased (p<0.05) such previous parameters. Decreasing MOLM inclusion levels in duckling diets increased (p>0.05) the digestibility of organic matter, crude protein, ether extract, and nitrogen free extract, however all MOLM treatments were significantly higher than the control group. Results also revealed that feeding ducks lower MOLM inclusion levels (0.25% or 0.50%) improved blood parameters (p<0.05) compared with the higher inclusion levels (1.0% or 2.0% MOLM) and the control group. Ducks fed different MOLM levels had significantly higher phagocyte index and activity, immunoglobulin G (IgG), IgM, total antioxidant capacity, glutathione peroxidase activity, and superoxide dismutase activity compared with control group. Conclusion: Despite the beneficial effects of all MOLM treatments on growth performance, nutrient digestibility, physiological status, and immune response of duckling, the increasing MOLM inclusion level in the diet had deleterious effects on such studied traits, consequently 0.25% was the best MOLM inclusion level in duckling diets.

• Horticultural Science & Technology
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• v.33 no.6
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• pp.911-922
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• 2015

This study was carried out to evaluate growth characteristics of Kimchi cabbage cultivated in various highland areas, and to create a predicting model for the production of highland Kimchi cabbage based on the growth parameters and climatic elements. Regression model for the estimation of head weight was designed with non-destructive measured growth variables (NDGV) such as leaf length (LL), leaf width (LW), head height (HH), head width (HW), and growing degree days (GDD), which was $y=6897.5-3.57{\times}GDD-136{\times}LW+116{\times}PH+155{\times}HH-423{\times}HW+0.28{\times}HH{\times}HW{\times}HW$, ($r^2=0.989$), and was improved by using compensation terms such as the ratio (LW estimated with GDD/measured LW ), leaf growth rate by soil moisture, and relative growth rate of leaf during drought period. In addition, we proposed Excel spreadsheet model for simulation of yield prediction of highland Kimchi cabbage. This Excel spreadsheet was composed four different sheets; growth data sheet measured at famer's field, daily average temperature data sheet for calculating GDD, soil moisture content data sheet for evaluating the soil water effect on leaf growth, and equation sheet for simulating the estimation of production. This Excel spreadsheet model can be practically used for predicting the production of highland Kimchi cabbage, which was calculated by (acreage of cultivation) ${\times}$ (number of plants) ${\times}$ (head weight estimated with growth variables and GDD) ${\times}$ (compensation terms derived relationship of GDD and growth by soil moisture) ${\times}$ (marketable head rate).

• Korean Journal of Medicinal Crop Science
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• v.16 no.6
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• pp.434-438
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• 2008

To selection of optimal shading material, two-year-old ginseng (Panax ginseng C. A. Meyer) of new cultivar, 'Cheonpoong' (CP), and native species 'Hwangsookjong' (HS) were cultured under three kinds of shading materials such as three-layered blue and a one-layered black PE (polyethylene) net (TBSB), blue PE sheet (BS), and aluminium coated PE sheet (AS) in imperfectly drained paddy soil. Growth characteristics, yield and ginsenoside contents were investigated under three shading materials. Yield and ginsenoside contents of ginseng were distinctly affected by intensity and quality of sunlight penetrated through shading materials. Light transmission ratio, air and soil temperature according to shading materials were higher in order of BS, AS, and TBSB. However, ratio of aerial phase and porosity of the soil were higher in order of AS, BS, and TBSB, respectively. There was no significantly difference in the ratio of rusty colored root by shading materials. CP showed higher stem length, leaf area, and root weight than that of HS, while the former showed distinctly lower discolored leaf ratio than that the other. Eight kinds of ginsenosides content of CP were higher than that of HS in $Rg_1$, Re, Rf, $Rb_1$ and Rc except $Rg_2$, $Rb_2$, and $Rb_3$. Total ginsenoside contents of CP was distinctly higher than that of HS. Total ginsenoside contents as affected by shading materials was higher in order of BS, TBSB, and AS in CP, while TBSB, BS, and AS in HS.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.231-236
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• 2022

The research was aimed to improve pre-harvest methods to maintain marketability in postharvest leaf lettuce. In this study, the effect of hydroponics on the growth and post-harvest storage characteristics of 'Chongchima' lettuce grown in peat mass medium hydroponic system using a non-powered culture device or deep water culture (DWC) was evaluated. There was no difference in fresh weight, leaf number, SPAD, moisture content, and C/N ratio between peat moss growing medium hydroponic and DWC methods except plant height. It was found that lettuce cultivation by a nonpowered hydroponics method is easier than the existing DWC. The quality parameters, such as fresh weight loss, SPAD value, and general appearance of lettuce were investigated after harvest. There was no significant difference in fresh weight loss and general appearance during storage of lettuce by the hydroponics methods. However, with the increased storage time of SPAD, which is related to chlorophyll content, was slightly higher in peat moss medium hydroponic was than DWC. When crops such as lettuce are grown under favorable conditions without any agronomic abnormalities, it is suggested that post-harvest storage is not significantly affected by peat moss growing medium hydroponic and DWC.

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.51-55
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• 2002

Green peppers (Capsicum annuum L. cv, Soonjung) were grown under different combinations of $CO_2$ concentration and temperature levels and examined on the effect of elevated $CO_2$ and temeprature on plant growth, carbon and nitrogen concentrations. Plant height was stimulated by elevated $CO_2$ levels at 20.3 and 22.6$^{\circ}C$. Leaf area and fresh weight were remarkedly increased by high $CO_2$ concentration at 22.6$^{\circ}C$. Dry weights of leaf, stem, root, and whole plant were increased as temperature increased at 611 ppm $CO_2$, but those values decreased at 22.6$^{\circ}C$ in 397 ppm $CO_2$ concentration. Elevated $CO_2$ increased plant growth by 1.5 times at 20.5$^{\circ}C$ and 22.6$^{\circ}C$. C/N ratio increased with increasing temperature under elevated $CO_2$ levels.